Assessing the Effectiveness of a Novel Contact Lens (Ortho C) on Paediatric Nearsightedness and Mood

The intervention is based on a rigid contact lens without any prescription. The treatment is named orthokeratology (or ortho C) to differentiate it from an existing contact lens treatment on the market known as ortho K. An ortho C lens is designed according to the participant's cornea curvature. A cornea curvature measurement called a k reading (or keratometer reading) will be taken prior to fitting an ortho C lens. The curvature of the cornea is different on every eye. The cornea curvature of the right eye is usually different from the left eye, and the cornea curvature of one participant is different from another. It is necessary to take a cornea curvature measurement call a k reading (or keratometer reading) prior to fitting a generic or ortho C lens. This will be performed using an autorefractor, and it takes approximately 5 minutes. The participant's forehead is placed against a headrest at the front and the chin is rested on a chinrest at the bottom. The participant would look at an image on a computer screen. I will operate the autorefractor to take the horizontal and vertical curvature of the cornea of each eye. I will design the lens based on the above information. The lens is slightly flatter than the average curvature of the cornea. The average curvature is the average between the horizontal and vertical cornea readings taken with the autorefractor. The measurements are expressed in diopters. The flatness of the lens is according to the absolute value of the prescription of the eye. If the prescription is -0.50 D, the curvature of the lens is 0.50 D flatter. If it is -0.75 D, the curvature of the lens is 0.75 D flatter, etc. The maximum flatness is 2.0 D. The diameter of the lens is generally 9.2 mm. There is no prescription. It is a plain lens. The thickness is 0.15 mm. It is within the specification of Stein, Slatt, Stein, and Freeman (2002). The specifications for the curvature of the lens varies for each individual. The specifications for the power and the thickness is fixed. The lens is a rigid gas permeable lens. The material is made by Bausch and Lomb. The type of material is Boston EO. The above parameters of a lens for each participant is sent to an optical lab in Toronto: Optik K and R. The time it takes to design the lens is about 15 minutes. The time it takes to manufacture the lens is about a week. It is designed to last for a life time. But the participant will not need to wear the lenses after 1 or 2 years. The following steps 1 to 4 are performed first before applying the intervention: 1. Perform a visual acuity test to establish benchmark. 2. Have the participant complete the following assessments: Mood Assessment Sheet, the Hare Self-Esteem assessment, and the Kidscreen Quality of Life assessment. 3. Measure the participant's cornea curvature. 4. Design the lens according to the cornea curvature. The following steps of the intervention consists of the Distant Drill and the Snellen chart drill. The following steps 5 to 7 are performed after receiving the lens from the lab: 5. One lens is worn on the better eye first. The participant will perform the Distant Drill first by looking at a distant object outdoors at approximately 300 feet for 30 seconds. The other eye is covered. The lens is then removed. The participant will then perform the Snellen chart drill by reading the 20/25 line on a Snellen chart (which is calibrated for 10 feet) for five times at 5 feet away. The procedure is repeated on the other eye. 6. Take another visual acuity test and compare it to the benchmark reading taken in step 1 to determine the improvement in visual acuity. This is done at the end of every follow-up period. 7, During the last follow-up, have the participant complete again the Mood Assessment Sheet, the Hare Self-Esteem assessment, and the Kidscreen Quality of Life assessment. The participant will wear the lens on one eye at a time. It is worn just once to perform the intervention on the first day of each follow-up period. I will insert the lens onto children when they come to see me. I will teach adolescents how to insert and remove the lens with a contact lens remover. I will teach them how to keep the lens clean to avoid eye infection. The wearing duration of each lens (how long the lens is on the cornea before it is removed) is about 1 minute. I will supervise the drill the participant will perform with the lens on to ensure it is according to protocol. I will instruct the participant on how to avoid near-point stress. They will not wear a minus lens which is designed for the distance for near work. When engaging in prolonged near work, they will follow the 20/20 rule: look away every 20 minutes to focus on an object beyond 20 feet for 20 seconds. The wearing frequence (how often to wear the lens) is once a week (for 4 visits) and then once every 2 weeks (for 3 visits). The following are the scheduled follow-up periods: The first interval is 1 week apart. We would meet 4 times (once per week). The next interval is 2 weeks apart. We would meet 3 times (once every two weeks. The wearing duration (how long the lens is on the cornea) is about a minute. The duration is made up of the following: The time it takes to position oneself 3 feet from the window and look at the object of regard 300 feet away. The time it takes to perform the intervention. The time it takes to position oneself in front of a mirror to remove the lens with a contact lens remover. Delivering the Intervention Study procedures will be completed by an optician.